These lasers take aligning rollers from the traditional multi-tool, multi-person job to a one-tool, one-person job. Strap the transmitter to the roller you want to match and the receiver to the roller you want to check. Instead of aligning with lots of trial and error, these tools have a horizontal beam that shows if your rollers are aligned in the same plane, and a vertical beam that shows if the rollers are evenly spaced along their length. Simply adjust the roller until the beams line up with the tools' reference points.

In addition to being easy to use, these lasers were also designed to be useful in most roller setups. The adjustable straps allow you to secure them to different roller sizes and materials. They're also compact enough to fit in tight spaces between rollers.